The carburetor is vacuum produced in the engine work; the gasoline can be mixed with air for a certain proportion. The carburetor, as a precision device, plays an important role in the engine and can be called “the heart of the engine”. The device should include a starting device, idle device, and throttle control device. According to the requirements of the different work state for the engine, the carburetor automatically matches the corresponding mixed gas concentration, puts out the corresponding amount of mixed gas, in order to make the distribution of the mixed gas mixed evenly, and the carburetor has the effect of fuel atomization, for the normal operation of the machine.
In order to make the carburetor always work stably in the optimum mixture ratio of the fuel and air, usually carburetor manufacturers in the carburetor factory have the carburetor fuel and air mixing ratio adjusted to the optimal state, which can not only play the best working performance of the engine, and significantly extend the carburetor normal working life, but also make the carburetor reach optimal oil state at work, thus greatly saving fuel resources. In order to enable the carburetor to be stable in the optimum mixture ratio of the fuel and air, and play the optimal performance of engine, and also to substantially extend the carburetor normal service life and save fuel resources, it is necessary to set up an anti-adjusting mechanism on the carburetor to prevent non-specialized users from randomly adjusting the fuel and air mixing proportion of the carburetor. However, existing carburetors cannot meet the above requirements. For example, U.S. Pat. No. 6,394,424 discloses a rotary valve carburetor, including: the structure of the regulating head of the idle adjustment oil needle is linear type, and a steel ball is pressed on the top of the regulation structure; this anti-adjusting structure is very complex, economic performance is very poor, and engine manufacturers or carburetor manufacturers will not be able to adjust the idle oil needle when they need to adjust the carburetor technical parameters.